15.1 The Capital Structure Question and the Pie Theory
How should a firm choose its debt–equity ratio? We call our approach to the capital structure question the pie model. If you are wondering why we chose this name, just take a look at Fig. 15.1. The pie in question is the sum of the financial claims of the firm - debt and equity in this case. We define the value of the firm to be this sum. Hence the value of the firm, V, is
where B is the market value of the debt and S is the market value of the equity. Figure 15.1 presents two possible ways of slicing this pie between equity and debt: 40 per cent/60 per cent and 60 per cent/40 per cent. If the goal of a firm’s management is to make the firm as valuable as possible, then the firm should pick the debt–equity ratio that makes the pie – the total value – as big as possible.
This discussion begs two important questions:
- Why should the shareholders in the firm care about maximizing the value of the entire firm? After all, the value of the firm is, by definition, the sum of both the debt and the equity. Instead, why should the shareholders not prefer the strategy that maximizes their interests only?
- What ratio of debt to equity maximizes the shareholders’ interests?
Let us examine each of the two questions in turn.
|Figure 15.1||Two pie models of capital structure|
15.2 Maximizing Firm Value versus Maximizing Shareholder Interests
The following example shows that the capital structure that maximizes the value of the firm is the one that financial managers should choose for the shareholders.
This example explains why managers should attempt to maximize the value of the firm. In other words, it answers question 1 in Section 15.1. We find in this example the following wisdom:
Changes in capital structure benefit the shareholders if and only if the value of the firm increases.
Conversely, these changes hurt the shareholders if and only if the value of the firm decreases. This result holds true for capital structure changes of many different types.1 As a corollary, we can say the following:
Managers should choose the capital structure that they believe will have the highest firm value because this capital structure will be most beneficial to the firm’s shareholders.
Note, however, that this example does not tell us which of the three outcomes is most likely to occur. Thus it does not tell us whether debt should be added to J.J. Sprint’s capital structure. In other words, it does not answer question 2 in Section 15.1. This second question is treated in the next section.
15.3 Financial Leverage and Firm Value: An Example
Leverage and Returns to ShareholdersThe previous section shows that the capital structure producing the highest firm value is the one that maximizes shareholder wealth. In this section we wish to determine that optimal capital structure. We begin by illustrating the effect of capital structure on returns to shareholders. We shall use a detailed example, which we encourage students to study carefully. Once we fully understand this example, we shall be ready to determine the optimal capital structure.
Autoveloce SpA currently has no debt in its capital structure. The firm is considering issuing debt to buy back some of its equity. Both its current and proposed capital structures are presented in Table 15.1. The firm’s assets are €8,000. There are 400 shares of the all-equity firm, implying a market value per share of €20. The proposed debt issue is for €4,000, leaving €4,000 in equity. The interest rate is 10 per cent. Assume in all our examples that debt is issued at par.
The effect of economic conditions on earnings per share is shown in Table 15.2 for the current capital structure (all equity). Consider first the middle column, where earnings are expected to be €1,200. Because assets are €8,000, the return on assets (ROA) is 15 per cent (= €1,200/€8,000). Assets equal equity for this all-equity firm, so return on equity (ROE) is also 15 per cent. Earnings per share (EPS) is €3.00 (= €1,200/400). Similar calculations yield EPS of €1.00 and €5.00 in the cases of recession and expansion, respectively.
The case of leverage is presented in Table 15.3. ROA in the three economic states is iden-tical in Tables 15.2 and 15.3, because this ratio is calculated before interest is considered. Debt is €4,000 here, so interest is €400 (= 0.10 × €4,000). Thus earnings after interest are €800 (= €1,200 − €400) in the middle (expected) case. Because equity is €4,000, ROE is 20 per cent (= €800/€4,000). Earnings per share are €4.00 (= €800/200). Similar calculations yield earnings of €0 and €8.00 for recession and expansion, respectively.
Tables 15.2 and 15.3 show that the effect of financial leverage depends on the company’s earnings before interest. If earnings before interest are equal to €1,200, the return on equity (ROE) is higher under the proposed structure. If earnings before interest are equal to €400, the ROE is higher under the current structure.
This idea is represented in Fig. 15.2. The solid line represents the case of no leverage. The line begins at the origin, indicating that earnings per share (EPS) would be zero if earnings before interest (EBI) were zero. The EPS rise in tandem with a rise in EBI.
The dotted line represents the case of €4,000 of debt. Here EPS are negative if EBI are zero. This follows because €400 of interest must be paid, regardless of the firm’s profits.
Now consider the slopes of the two lines. The slope of the dotted line (the line with debt) is higher than the slope of the solid line. This occurs because the levered firm has fewer shares of equity outstanding than the unlevered firm. Therefore any increase in EBI leads to a greater rise in EPS for the levered firm, because the earnings increase is distributed over fewer shares of equity.
Because the dotted line has a lower intercept but a higher slope, the two lines must intersect. The break-even point occurs at €800 of EBI. Were earnings before interest to be €800, both firms would produce €2 of earnings per share (EPS). Because €800 is break-even, earnings above €800 lead to greater EPS for the levered firm. Earnings below €800 lead to greater EPS for the unlevered firm.
The Choice between Debt and EquityTables 15.2 and 15.3 and Fig. 15.2 are important, because they show the effect of leverage on earnings per share. Students should study the tables and figure until they feel comfortable with the calculation of each number in them. However, we have not yet presented the punch line. That is, we have not yet stated which capital structure is better for Autoveloce.
At this point many students believe that leverage is beneficial, because EPS are expected to be €4.00 with leverage and only €3.00 without leverage. However, leverage also creates risk. Note that in a recession EPS are higher (€1.00 versus €0) for the unlevered firm. Thus a risk-averse investor might prefer the all-equity firm, whereas a risk-neutral (or less risk-averse) investor might prefer leverage. Given this ambiguity, which capital structure is better?
Modigliani and Miller (MM or M & M) have a convincing argument that a firm cannot change the total value of its outstanding securities by changing the proportions of its capital structure. In other words, the value of the firm is always the same under different capital structures. In still other words, no capital structure is any better or worse than any other capital structure for the firm’s shareholders. This rather pessimistic result is the famous MM Proposition I.2
Their argument compares a simple strategy, which we call strategy A, with a two-part strategy, which we call strategy B. Both of these strategies for shareholders of Autoveloce are illustrated in Table 15.4. Let us now examine the first strategy.
Strategy A: Buy 100 shares of the levered equity
The first line in the top panel of Table 15.4 shows EPS for the proposed levered equity in the three economic states. The second line shows the earnings in the three states for an individual buying 100 shares. The next line shows that the cost of these 100 shares is €2,000.
Let us now consider the second strategy, which has two parts to it.
Strategy B: Homemade leverage
Now let us compare these two strategies, both in terms of earnings per year and in terms of initial cost. The top panel of the table shows that strategy A generates earnings of €0, €400 and €800 in the three states. The bottom panel of the table shows that strategy B generates the same net earnings in the three states.
The top panel of the table shows that strategy A involves an initial cost of €2,000. Similarly, the bottom panel shows an identical net cost of €2,000 for strategy B.
This shows a very important result. Both the cost and the pay-off from the two strategies are the same. Thus we must conclude that Autoveloce is neither helping nor hurting its shareholders by restructuring. In other words, an investor is not receiving anything from corporate leverage that she could not receive on her own.
Note that, as shown in Table 15.1, the equity of the unlevered firm is valued at €8,000. Because the equity of the levered firm is €4,000 and its debt is €4,000, the value of the levered firm is also €8,000. Now suppose that, for whatever reason, the value of the levered firm were actually greater than the value of the unlevered firm. Here strategy A would cost more than strategy B. In this case an investor would prefer to borrow on his own account and invest in the equity of the unlevered firm. He would get the same net earnings each year as if he had invested in the equity of the levered firm. However, his cost would be less. The strategy would not be unique to our investor. Given the higher value of the levered firm, no rational investor would invest in the shares of the levered firm. Anyone desiring shares in the levered firm would get the same euro return more cheaply by borrowing to finance a purchase of the unlevered firm’s shares. The equilibrium result would be, of course, that the value of the levered firm would fall and the value of the unlevered firm would rise until they became equal. At this point individuals would be indifferent between strategy A and strategy B.
This example illustrates the basic result of Modigliani–Miller (MM) and is, as we have noted, commonly called their Proposition I. We restate this proposition as follows:
MM Proposition I (no taxes): The value of the levered firm is the same as the value of the unlevered firm.
This is perhaps the most important result in all of corporate finance. In fact, it is generally considered the beginning point of modern corporate finance. Before MM, the effect of leverage on the value of the firm was considered complex and convoluted. Modigliani and Miller showed a blindingly simple result: if levered firms are priced too high, rational investors will simply borrow on their personal accounts to buy shares in unlevered firms. This substitution is oftentimes called homemade leverage. As long as individuals borrow (and lend) on the same terms as the firms, they can duplicate the effects of corporate leverage on their own.
The example of Autoveloce SpA shows that leverage does not affect the value of the firm. Because we showed earlier that shareholders’ welfare is directly related to the firm’s value, the example also indicates that changes in capital structure cannot affect the shareholders’ welfare.
A Key AssumptionThe MM result hinges on the assumption that individuals can borrow as cheaply as corporations. If, alternatively, individuals can borrow only at a higher rate, we can easily show that corporations can increase firm value by borrowing.
Is this assumption of equal borrowing costs a good one? Individuals who want to buy shares and borrow can do so by establishing a margin account with a broker. Under this arrangement the broker lends the individual a portion of the purchase price. For example, the individual might buy €10,000 of equity by investing €6,000 of her own funds and borrowing €4,000 from the broker. Should the shares be worth €9,000 on the next day, the individual’s net worth or equity in the account would be €5,000 = €9,000 - €4,000.3
The broker fears that a sudden price drop will cause the equity in the individual’s account to be negative, implying that the broker may not get her loan repaid in full. To guard against this possibility, stock exchange rules require that the individual make additional cash contributions (replenish her margin account) as the share price falls. Because (a) the procedures for replenishing the account have developed over many years and (b) the broker holds the equity as collateral, there is little default risk to the broker. In particular, if margin contributions are not made on time, the broker can sell the shares to satisfy her loan. Therefore brokers generally charge low interest, with many rates being only slightly above the risk-free rate.
By contrast, corporations frequently borrow using illiquid assets (e.g. plant and equipment) as collateral. The costs to the lender of initial negotiation and ongoing supervision, as well as of working out arrangements in the event of financial distress, can be quite substantial. Thus it is difficult to argue that individuals must borrow at higher rates than corporations.
15.4 Modigliani and Miller: Proposition II (No Taxes)
Risk to Equity-holders Rises with LeverageAt an Autoveloce board meeting a director said, “Well, maybe it does not matter whether the corporation or the individual levers - as long as some leverage takes place. Leverage benefits investors. After all, an investor’s expected return rises with the amount of the leverage present.” He then pointed out that, as shown in Tables 15.2 and 15.3, the expected return on unlevered equity is 15 per cent, whereas the expected return on levered equity is 20 per cent.
However, another director replied, “Not necessarily. Though the expected return rises with leverage, the risk rises as well.” This point can be seen from an examination of Tables 15.2 and 15.3. With earnings before interest (EBI) varying between €400 and €2,000, earnings per share (EPS) for the shareholders of the unlevered firm vary between €1.00 and €5.00. EPS for the shareholders of the levered firm vary between €0 and €8.00. This greater range for the EPS of the levered firm implies greater risk for the levered firm’s shareholders. In other words, levered shareholders have better returns in good times than do unlevered shareholders, but have worse returns in bad times. The two tables also show greater range for the ROE of the levered firm’s shareholders. The earlier interpretation concerning risk applies here as well.
The same insight can be taken from Fig. 15.2. The slope of the line for the levered firm is greater than the slope of the line for the unlevered firm. This means that the levered shareholders have better returns in good times than do unlevered shareholders, but have worse returns in bad times, implying greater risk with leverage. In other words, the slope of the line measures the risk to shareholders, because the slope indicates the responsiveness of ROE to changes in firm performance (earnings before interest).
Proposition II: Required Return to Equity-holders Rises with LeverageBecause levered equity has greater risk, it should have a greater expected return as compensation. In our example, the market requires only a 15 per cent expected return for the unlevered equity, but it requires a 20 per cent expected return for the levered equity.
This type of reasoning allows us to develop MM Proposition II. Here MM argue that the expected return on equity is positively related to leverage, because the risk to equity-holders increases with leverage.
To develop this position, recall that the firm’s weighted average cost of capital, RWACC, can be written as4
where RB is the cost of debt; RS is the expected return on equity, also called the cost of equity or the required return on equity; RWACC is the firm’s weighted average cost of capital; B is the market value of the firm’s debt or bonds; and S is the market value of the firm’s shares or equity.
Equation (15.2) is quite intuitive. It simply says that a firm’s weighted average cost of capital is a weighted average of its cost of debt and its cost of equity. The weight applied to debt is the proportion of debt in the capital structure, and the weight applied to equity is the proportion of equity in the capital structure. Calculations of RWACC from Eq. (15.2) for both the unlevered and the levered firm are presented in Table 15.5.
An implication of MM Proposition I is that RWACC is a constant for a given firm, regardless of the capital structure.5 For example, Table 15.5 shows that RWACC for Autoveloce is 15 per cent, with or without leverage.
Let us now define R0 to be the cost of capital for an all-equity firm. For Autoveloce SpA, R0 is calculated as
As can be seen from Table 15.5, RWACC is equal to R0 for Autoveloce. In fact, RWACC must always equal R0 in a world without corporate taxes.
Proposition II states the expected return on equity, RS, in terms of leverage. The exact relationship, derived by setting RWACC = R0 and then rearranging Eq. (15.2), is6
MM Proposition II (no taxes):
Equation (15.3) implies that the required return on equity is a linear function of the firm’s debt–equity ratio. Examining Eq. (15.3), we see that if R0 exceeds the cost of debt, RB, then the cost of equity rises with increases in the debt–equity ratio, B/S. Normally R0 should exceed RB. That is, because even unlevered equity is risky, it should have an expected return greater than that of riskless debt. Note that Eq. (15.3) holds for Autoveloce in its levered state:
Figure 15.3 graphs Eq. (15.3). As you can see, we have plotted the relation between the cost of equity, RS, and the debt–equity ratio, B/S, as a straight line. What we witness in Eq. (15.3) and illustrate in Fig. 15.3 is the effect of leverage on the cost of equity. As the firm raises the debt–equity ratio, each euro of equity is levered with additional debt. This raises the risk of equity and therefore the required return, RS, on the equity.
Figure 15.3 also shows that RWACC is unaffected by leverage, a point we have already made. (It is important for students to realize that R0, the cost of capital for an all-equity firm, is represented by a single dot on the graph. By contrast, RWACC is an entire line.)
MM: An InterpretationThe Modigliani–Miller results indicate that managers cannot change the value of a firm by repackaging the firm’s securities. Though this idea was considered revolutionary when it was originally proposed in the late 1950s, the MM approach and proof have since met with wide acclaim.7
MM argue that the firm’s overall cost of capital cannot be reduced as debt is substituted for equity, even though debt appears to be cheaper than equity. The reason for this is that, as the firm adds debt, the remaining equity becomes more risky. As this risk rises, the cost of equity capital rises as a result. The increase in the cost of the remaining equity capital offsets the higher proportion of the firm financed by low-cost debt. In fact, MM prove that the two effects exactly offset each other, so that both the value of the firm and the firm’s overall cost of capital are invariant to leverage.
Food found its way into this chapter earlier when we viewed the firm as a pie. MM argue that the size of the pie does not change, no matter how shareholders and bondholders divide it. MM say that a firm’s capital structure is irrelevant; it is what it is by some historical accid-ent. The theory implies that firms’ debt–equity ratios could be anything. They are what they are because of whimsical and random managerial decisions about how much to borrow and how much equity to issue.
Although scholars are always fascinated with far-reaching theories, students are perhaps more concerned with real-world applications. Do real-world managers follow MM by treating capital structure decisions with indifference? Unfortunately for the theory, virtually all companies in certain industries, such as banking, choose high debt–equity ratios. Conversely, companies in other industries, such as pharmaceuticals, choose low debt–equity ratios. In fact, almost any industry has a debt–equity ratio to which companies in that industry tend to adhere. Thus companies do not appear to be selecting their degree of leverage in a frivolous or random manner. Because of this, financial economists (including MM themselves) have argued that real-world factors may have been left out of the theory.
Though many of our students have argued that individuals can borrow only at rates above the corporate borrowing rate, we disagreed with this argument earlier in the chapter. But when we look elsewhere for unrealistic assumptions in the theory, we find two:8
15.5 Corporate Taxes
The Basic InsightThe previous part of this chapter showed that firm value is unrelated to debt in a world without taxes. We now show that in the presence of corporate taxes the firm’s value is positively related to its debt. The basic intuition can be seen from a pie chart, such as the one in Fig. 15.4. Consider the all-equity firm on the left. Here both shareholders and tax authorities have claims on the firm. The value of the all-equity firm is, of course, that part of the pie owned by the shareholders. The proportion going to taxes is simply a cost.
The pie on the right for the levered firm shows three claims: shareholders, debtholders, and taxes. The value of the levered firm is the sum of the value of the debt and the value of the equity. In selecting between the two capital structures in the picture, a financial manager should select the one with the higher value. Assuming that the total area is the same for both pies,9 value is maximized for the capital structure paying the least in taxes. In other words, the manager should choose the capital structure that the government hates the most.
We shall show that, because of a quirk in corporate tax law, the proportion of the pie allocated to taxes is less for the levered firm than it is for the unlevered firm. Thus managers should select high leverage.
Present Value of the Tax ShieldThe previous discussion shows a tax advantage to debt or, equivalently, a tax disadvantage to equity. We now want to value this advantage. The interest in monetary terms is
This interest is €400,000 (= 10% × €4,000,000) for Wasserprodukte. All this interest is tax-deductible. That is, whatever the taxable income of Wasserprodukte would have been without the debt, the taxable income is now €400,000 less with the debt.
Because the corporate tax rate is 0.35 in our example, the reduction in corporate taxes is €140,000 (= 0.35 × €400,000). This number is identical to the reduction in corporate taxes calculated previously.
Algebraically, the reduction in corporate taxes is
That is, whatever the taxes that a firm would pay each year without debt, the firm will pay tCRBB less with the debt of B. Expression (15.4) is often called the tax shield from debt. Note that it is an annual amount.
As long as the firm expects to be paying tax, we can assume that the cash flow in Expression (15.4) has the same risk as the interest on the debt. Thus its value can be determined by discounting at the cost of debt, RB. Assuming that the cash flows are perpetual, the present value of the tax shield is
Value of the Levered FirmWe have just calculated the present value of the tax shield from debt. Our next step is to calculate the value of the levered firm. The annual after-tax cash flow of an unlevered firm is
where EBIT is earnings before interest and taxes. The value of an unlevered firm (that is, a firm with no debt) is the present value of EBIT × (1 - tC):
Here VU is the present value of an unlevered firm; EBIT × (1 - tC) represents firm cash flows after corporate taxes; tC is the corporate tax rate; and R0 is the cost of capital to an all-equity firm. As can be seen from the formula, R0 now discounts after-tax cash flows.
As shown previously, leverage increases the value of the firm by the tax shield, which is tCB for perpetual debt. Thus we merely add this tax shield to the value of the unlevered firm to get the value of the levered firm.
We can write this algebraically as follows:11
MM Proposition I (corporate taxes):
Equation (15.5) is MM Proposition I under corporate taxes. The first term in Eq. (15.5) is the value of the cash flows of the firm with no debt tax shield. In other words, this term is equal to VU, the value of the all-equity firm. The value of the levered firm is the value of an all-equity firm plus tCB, the tax rate times the value of the debt. tCB is the present value of the tax shield in the case of perpetual cash flows.12 Because the tax shield increases with the amount of debt, the firm can raise its total cash flow and its value by substituting debt for equity.
Expected Return and Leverage under Corporate TaxesMM Proposition II under no taxes proposes a positive relationship between the expected return on equity and leverage. This result occurs because the risk of equity increases with leverage. The same intuition also holds in a world of corporate taxes. The exact formula in a world of corporate taxes is this:13
MM Proposition II (corporate taxes):
Applying the formula to Divided Airlines, we get
This calculation is illustrated in Fig. 15.6.
Whenever R0 > RB, RS increases with leverage, a result that we also found in the no-tax case. As stated earlier in this chapter, R0 should exceed R0B. That is, because equity (even un-levered equity) is risky, it should have an expected return greater than that on the less risky debt.
Let’s check our calculations by determining the value of the levered equity in another way. The algebraic formula for the value of levered equity is
The numerator is the expected cash flow to levered equity after interest and taxes. The denominator is the rate at which the cash flow to equity is discounted.
For Divided Airlines we get
which is the same result we obtained earlier (ignoring a small rounding error).
The Weighted Average Cost of Capital, RWACC, and Corporate TaxesIn Chapter 12 we defined the weighted average cost of capital (with corporate taxes) as follows (note that VL = S + B):
Note that the cost of debt capital, RB, is multiplied by (1 - tC), because interest is tax-deductible at the corporate level. However, the cost of equity, RS, is not multiplied by this factor, because dividends are not deductible. In the no-tax case RWACC is not affected by leverage. This result is reflected in Fig. 15.3, which we discussed earlier. However, because debt is tax-advantaged relative to equity, it can be shown that RWACC declines with leverage in a world with corporate taxes. This result can be seen in Fig. 15.6.
For Divided Airlines, RWACC is equal to
Divided Airlines has reduced its RWACC from 0.20 (with no debt) to 0.1754 with reliance on debt. This result is intuitively pleasing, because it suggests that when a firm lowers its RWACC, the firm’s value will increase. Using the RWACC approach, we can confirm that the value of Divided Airlines is €570:
Share Prices and Leverage under Corporate TaxesAt this point students often believe the numbers - or at least are too intimidated to dispute them. However, they sometimes think we have asked the wrong question. “Why are we choosing to maximize the value of the firm?” they will say. “If managers are looking out for the shareholders’ interests, why aren’t they trying to maximize share price?” If this question occurred to you, you have come to the right section.
Our response is twofold. First, we showed in the first section of this chapter that the capital structure that maximizes firm value is also the one that most benefits the interests of the shareholders.
However, that general explanation is not always convincing to students. As a second procedure, we calculate the share price of Divided Airlines both before and after the exchange of debt for equity. We do this by presenting a set of market value balance sheets. The market value balance sheet for the company in its all-equity form can be represented as follows:
Assuming that there are 100 shares outstanding, each share is worth €5 = €500/100.
Next imagine the company announces that in the near future it will issue €200 of debt to buy back €200 of equity. We know from our previous discussion that the value of the firm will rise to reflect the tax shield of debt. If we assume that capital markets price securities efficiently, the increase occurs immediately. That is, the rise occurs on the day of the announcement, not on the date of the debt-for-equity exchange. The market value balance sheet now becomes this:
Note that the debt has not yet been issued. Therefore only equity appears on the right side of the balance sheet. Each share is now worth €570/100 = €5.70, implying that the shareholders have benefited by €70. The shareholders gain because they are the owners of a firm that has improved its financial policy.
The introduction of the tax shield to the balance sheet is perplexing to many students. Although physical assets are tangible, the ethereal nature of the tax shield bothers these students. However, remember that an asset is any item with value. The tax shield has value because it reduces the stream of future taxes. The fact that one cannot touch the shield in the way that one can touch a physical asset is a philosophical, not a financial, consideration.
At some point the exchange of debt for equity occurs. Debt of €200 is issued, and the proceeds are used to buy back shares. How many shares are repurchased? Because shares are now selling at €5.70 each, the number of shares that the firm acquires is €200/€5.70 = 35.09. This leaves 64.91 (= 100 − 35.09) shares outstanding. The market value balance sheet is now this:
Each share is worth €370/64.91 = €5.70 after the exchange. Notice that the share price does not change on the exchange date. As we mentioned, the share price moves on the date of the announcement only. Because the shareholders participating in the exchange receive a price equal to the market price per share after the exchange, they do not care whether they exchange their equity.
This example was provided for two reasons. First, it shows that an increase in the value of the firm from debt financing leads to an increase in the price of the shares. In fact, the shareholders capture the entire €70 tax shield. Second, we wanted to provide more work with market value balance sheets.
A summary of the main results of Modigliani–Miller with corporate taxes is presented in the following boxed section:
15.6 Personal TaxesSo far in this chapter we have considered corporate taxes only. Because interest on debt is tax-deductible, whereas dividends on equity are not deductible, we argued that the tax system gives firms an incentive to issue debt. But corporations are not the only ones paying taxes; individuals must pay taxes on both the dividends and the interest that they receive. We cannot fully understand the effect of taxes on capital structure until all taxes, both corporate and personal, are considered.
The Basics of Personal TaxesLet’s begin by examining an all-equity firm that receives €1 of pre-tax earnings. If the corporate tax rate is tc, the firm pays taxes tc, leaving itself with earnings after taxes of 1 - tC. Let’s assume that this entire amount is distributed to the shareholders as dividends. If the personal tax rate on share dividends is tS, the shareholders pay taxes of (1 - tC) × tS, leaving them with (1 - tC) × (1 - tS) after taxes.
Alternatively, imagine that the firm is financed with debt. Here, the entire €1 of earnings will be paid out as interest, because interest is deductible at the corporate level. If the personal tax rate on interest is tB, the bondholders pay taxes of tB, leaving them with 1 - tB after taxes.
The Effect of Personal Taxes on Capital StructureTo explore the effect of personal taxes on capital structure, let’s consider three questions: